Hello,
I don’t know if it’s possible, I hope together we can find out if and why. It’s a small displacement motorcycle (100cc), and it has successfully been done before (links further down), but my research so far seems to indicate that my generator doesn’t have enough power, and not just by a little, but like by a lot not enough: someone calculated for me that i need about a 1000 Watts (since the alternator sits on the crankshaft, there’s no gearing, unlike with a traditional starter) and that my generator won’t be stronger than a 30 Watt motor.
How did he get those numbers? I don’t exactly know how he got the 1000 Watts needed to crank the engine, but it doesn’t seem outlandish. The 30 Watts at low rpm are an estimate we made, knowing that the generator is barely able to power the 12V30Watts headlamp at idle (it’s wired directly to the alternator and the bulb is just on, very very dimly, at idle. It needs almost about 1500 rpm to shine at full brightness).
Here’s the part I totally don’t understand: the generator can’t possibly be 33 times too weak than it theoretically needed to be, I guess I must take the voltage into account before I can compare these number, but how?
Then, I have found out that there have been a few Japanese motorbikes that used such a starter generator, in the 1970s. Those were small displacement bikes just like mine (100-200), and apparently while the starters weren’t the best (strongest) starters, they were reliable.
I know that these bikes were using generator-starters with electromagnets, while mine has a permanent magnet, but I guess that’s not a disadvantage for this project? Also, the alternator in the pictures had been converted to 3-phases, what difference does it make for the conversion? Because obviously, I could just as easily get an unmodified one. Other than that, I can’t see what so special about the generator-starters in the diagrams, that it couldn’t be done again, relatively easy. But maybe that’s because I don’t enough understanding, so I hope someone can help me out.
Here are the pictures of the alternator i want to convert:
https://postimg.cc/gallery/f7siwac0/And here’s a link to a page with diagrams for the starter-generators of some Japanese bikes
http://www.dansmc.com/genstarter.htm
I don’t know if it’s possible, I hope together we can find out if and why. It’s a small displacement motorcycle (100cc), and it has successfully been done before (links further down), but my research so far seems to indicate that my generator doesn’t have enough power, and not just by a little, but like by a lot not enough: someone calculated for me that i need about a 1000 Watts (since the alternator sits on the crankshaft, there’s no gearing, unlike with a traditional starter) and that my generator won’t be stronger than a 30 Watt motor.
How did he get those numbers? I don’t exactly know how he got the 1000 Watts needed to crank the engine, but it doesn’t seem outlandish. The 30 Watts at low rpm are an estimate we made, knowing that the generator is barely able to power the 12V30Watts headlamp at idle (it’s wired directly to the alternator and the bulb is just on, very very dimly, at idle. It needs almost about 1500 rpm to shine at full brightness).
Here’s the part I totally don’t understand: the generator can’t possibly be 33 times too weak than it theoretically needed to be, I guess I must take the voltage into account before I can compare these number, but how?
Then, I have found out that there have been a few Japanese motorbikes that used such a starter generator, in the 1970s. Those were small displacement bikes just like mine (100-200), and apparently while the starters weren’t the best (strongest) starters, they were reliable.
I know that these bikes were using generator-starters with electromagnets, while mine has a permanent magnet, but I guess that’s not a disadvantage for this project? Also, the alternator in the pictures had been converted to 3-phases, what difference does it make for the conversion? Because obviously, I could just as easily get an unmodified one. Other than that, I can’t see what so special about the generator-starters in the diagrams, that it couldn’t be done again, relatively easy. But maybe that’s because I don’t enough understanding, so I hope someone can help me out.
Here are the pictures of the alternator i want to convert:
https://postimg.cc/gallery/f7siwac0/And here’s a link to a page with diagrams for the starter-generators of some Japanese bikes
http://www.dansmc.com/genstarter.htm